Renewable silver-amalgam film electrode for voltammetric monitoring of solar photodegradation of imidacloprid in the presence of Fe/TiO2 and TiO2 catalysts

Voltammetric behavior and determination of the macrolide antibiotics azithromycin, clarithromycin and roxithromycin at a renewable silver – amalgam film electrode

“…Additionally, beside the elaborated analytical signals in all cases a broader reduction peak was observed at about À1.2 V. This signal was recognized at the appropriate baselines with same characteristics. As it was reported in our earlier papers [35,41,[47][48][49] this signal probably originates from the basic behavior of the Hg(Ag)FE in Britton-Robinson supporting electrolyte. Its presence was reported in acetate and phosphate buffer supporting electrolytes as well [47].…”

“…As it was reported in our earlier papers [35,41,[47][48][49] this signal probably originates from the basic behavior of the Hg(Ag)FE in Britton-Robinson supporting electrolyte. Its presence was reported in acetate and phosphate buffer supporting electrolytes as well [47]. Anyway, this signal has no significant overlapping character with the analytical signals in the case of all three macrolides till pH 10.…”

“…Before use, the surface of the Hg(Ag)FE was chemically cleaned in a 2% HNO 3 solution for about 5 min and then covered with a new amalgam film by immersing it in the internal amalgam pool of the electrode [47,48]. The Hg(Ag)FE required electrochemical activation before initial measurements in the chosen supporting electrolyte by cycling the potential in the range from À0.20 to À1.60 V over the course of around 20 cycles [35,41,47]. Furthermore, in every set of measurements, subsequent voltammetric curves were recorded for a renewed electrode surface, which was achieved by simply dipping the silver amalgam wire into the amalgam pool.…”

“…Recently, a renewable silver-amalgam film electrode (Hg(Ag)FE) was applied to study the reduction of EES, the analytical signal of which appeared in a fairly negative potential range, and a trace-level adsorptive stripping voltammetric method was used to determine its concentration in a selected pharmaceutical preparation and in a spiked urine sample [35]. It is well-known that the Hg(Ag)FE is a relatively new type of amalgam-based electrodes [36][37][38][39], and provides an alternative to the hanging mercury drop electrode due to their similar electrochemical characteristics [40]; the Hg(Ag)FE enables the determination of a wide range of analytes, including different organic compounds [35,[41][42][43][44][45][46][47][48][49][50][51][52][53][54]. For example, it was used for the determination of the levels of some medications, such as EES [35], doxorubicin [41], closantel [42], moroxydine [43], ambazone [44], proguanil [45], prednisolone [46] in spiked urine samples [35,41,[43][44][45] and in pharmaceutical preparation [35,42,[44][45][46].…”

“…For example, it was used for the determination of the levels of some medications, such as EES [35], doxorubicin [41], closantel [42], moroxydine [43], ambazone [44], proguanil [45], prednisolone [46] in spiked urine samples [35,41,[43][44][45] and in pharmaceutical preparation [35,42,[44][45][46]. The Hg(Ag)FE was also successfully applied for the quantitation of some neonicotinoid insecticides [47][48][49][50][51] in various matrices, such as spiked river water [48][49][50], commercial formulations [48,49], corn seed [50], spiked honey [48] and carrot juice [51]. Furthermore, the herbicide aclonifen was determined in spiked water samples and the fungicide fenoxanil in spiked river water and spiked rice samples [52,53].…”